Tarsus Pharmaceuticals, Inc. announced positive topline results from the Phase 2a Carpo trial evaluating TP-05 (lotilaner), a novel, investigational oral therapeutic for the prevention of Lyme disease. In this randomized, double-blind, placebo-controlled trial, the ability of TP-05 to kill ticks attached to subjects with a single treatment of TP-05 (low or high dose) was evaluated compared to placebo. Sterile, non-pathogenic nymphal ticks were placed on the skin of healthy human volunteers at two separate instances (one day prior to dosing and on Day 30 after dosing).

Tick mortality was evaluated within 24 hours of attachment after each placement. In most cases, ticks must be attached for 36-48 hours or more before Lyme disease can be transmitted, so killing ticks within 24 hours of attachment can greatly increase the probability of disease prevention. Both the high and low doses of TP-05 demonstrated a statistically significant benefit in killing ticks compared to placebo.

Specifically, after the Day 1 tick challenge, mean tick mortality was 97.0% (± 1.4 standard error, SE) and 92.0% (± 6.3 SE) for the high and low doses of TP-05, respectively, compared to only 5.0% (± 2.5 SE) for placebo (p < 0.0001). Similarly, at the 30-day challenge, mean tick mortality at 24 hours after placement was 89.0% (± 11.1 SE) and 91.0% (± 6.1 SE) for the high and low doses of TP-05, respectively, compared to only 9.0% (± 8.0 SE) for placebo (p<0.001). No statistically significant differences in tick mortality were observed between the two TP-05 treatment arms, and TP-05 was generally well tolerated.